Effective Use of Style Sheets
http://www.useit.com/alertbox/9707a.html

Nielsen, Jakob
Alertbox
2001

Abstract:

Cascading style sheets (CSS) are an elegantly designed extension to the Web and one of the greatest hopes for recapturing the Web's ideal of separation of presentation and content. The Web is the ultimate cross-platform system, and your content will be presented on such a huge variety of devices that pages should specify the meaning of the information and leave presentation details to a merger (or 'cascade') of site-specified style sheets and the user's preferences. If the introduction of WebTV broke your pages, you will appreciate the ability to introduce new page designs by creating a single style sheet file rather than by modifying thousands of content pages.